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0de967f2 | 1 | // SPDX-License-Identifier: GPL-2.0 |
6b775e87 JM |
2 | /* |
3 | * A power allocator to manage temperature | |
4 | * | |
5 | * Copyright (C) 2014 ARM Ltd. | |
6 | * | |
6b775e87 JM |
7 | */ |
8 | ||
9 | #define pr_fmt(fmt) "Power allocator: " fmt | |
10 | ||
11 | #include <linux/rculist.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/thermal.h> | |
14 | ||
6828a471 JM |
15 | #define CREATE_TRACE_POINTS |
16 | #include <trace/events/thermal_power_allocator.h> | |
17 | ||
6b775e87 JM |
18 | #include "thermal_core.h" |
19 | ||
8b7b390f JM |
20 | #define INVALID_TRIP -1 |
21 | ||
6b775e87 JM |
22 | #define FRAC_BITS 10 |
23 | #define int_to_frac(x) ((x) << FRAC_BITS) | |
24 | #define frac_to_int(x) ((x) >> FRAC_BITS) | |
25 | ||
26 | /** | |
27 | * mul_frac() - multiply two fixed-point numbers | |
28 | * @x: first multiplicand | |
29 | * @y: second multiplicand | |
30 | * | |
31 | * Return: the result of multiplying two fixed-point numbers. The | |
32 | * result is also a fixed-point number. | |
33 | */ | |
34 | static inline s64 mul_frac(s64 x, s64 y) | |
35 | { | |
36 | return (x * y) >> FRAC_BITS; | |
37 | } | |
38 | ||
39 | /** | |
40 | * div_frac() - divide two fixed-point numbers | |
41 | * @x: the dividend | |
42 | * @y: the divisor | |
43 | * | |
44 | * Return: the result of dividing two fixed-point numbers. The | |
45 | * result is also a fixed-point number. | |
46 | */ | |
47 | static inline s64 div_frac(s64 x, s64 y) | |
48 | { | |
49 | return div_s64(x << FRAC_BITS, y); | |
50 | } | |
51 | ||
52 | /** | |
53 | * struct power_allocator_params - parameters for the power allocator governor | |
f5cbb182 JM |
54 | * @allocated_tzp: whether we have allocated tzp for this thermal zone and |
55 | * it needs to be freed on unbind | |
6b775e87 JM |
56 | * @err_integral: accumulated error in the PID controller. |
57 | * @prev_err: error in the previous iteration of the PID controller. | |
58 | * Used to calculate the derivative term. | |
59 | * @trip_switch_on: first passive trip point of the thermal zone. The | |
60 | * governor switches on when this trip point is crossed. | |
8b7b390f JM |
61 | * If the thermal zone only has one passive trip point, |
62 | * @trip_switch_on should be INVALID_TRIP. | |
6b775e87 JM |
63 | * @trip_max_desired_temperature: last passive trip point of the thermal |
64 | * zone. The temperature we are | |
65 | * controlling for. | |
eda1ecfa LL |
66 | * @sustainable_power: Sustainable power (heat) that this thermal zone can |
67 | * dissipate | |
6b775e87 JM |
68 | */ |
69 | struct power_allocator_params { | |
f5cbb182 | 70 | bool allocated_tzp; |
6b775e87 JM |
71 | s64 err_integral; |
72 | s32 prev_err; | |
73 | int trip_switch_on; | |
74 | int trip_max_desired_temperature; | |
eda1ecfa | 75 | u32 sustainable_power; |
6b775e87 JM |
76 | }; |
77 | ||
e055bb0f JM |
78 | /** |
79 | * estimate_sustainable_power() - Estimate the sustainable power of a thermal zone | |
80 | * @tz: thermal zone we are operating in | |
81 | * | |
82 | * For thermal zones that don't provide a sustainable_power in their | |
83 | * thermal_zone_params, estimate one. Calculate it using the minimum | |
84 | * power of all the cooling devices as that gives a valid value that | |
85 | * can give some degree of functionality. For optimal performance of | |
86 | * this governor, provide a sustainable_power in the thermal zone's | |
87 | * thermal_zone_params. | |
88 | */ | |
89 | static u32 estimate_sustainable_power(struct thermal_zone_device *tz) | |
90 | { | |
91 | u32 sustainable_power = 0; | |
92 | struct thermal_instance *instance; | |
93 | struct power_allocator_params *params = tz->governor_data; | |
94 | ||
95 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
96 | struct thermal_cooling_device *cdev = instance->cdev; | |
97 | u32 min_power; | |
98 | ||
99 | if (instance->trip != params->trip_max_desired_temperature) | |
100 | continue; | |
101 | ||
8132df3a LL |
102 | if (!cdev_is_power_actor(cdev)) |
103 | continue; | |
104 | ||
105 | if (cdev->ops->state2power(cdev, instance->upper, &min_power)) | |
e055bb0f JM |
106 | continue; |
107 | ||
108 | sustainable_power += min_power; | |
109 | } | |
110 | ||
111 | return sustainable_power; | |
112 | } | |
113 | ||
114 | /** | |
115 | * estimate_pid_constants() - Estimate the constants for the PID controller | |
116 | * @tz: thermal zone for which to estimate the constants | |
117 | * @sustainable_power: sustainable power for the thermal zone | |
118 | * @trip_switch_on: trip point number for the switch on temperature | |
119 | * @control_temp: target temperature for the power allocator governor | |
e055bb0f JM |
120 | * |
121 | * This function is used to update the estimation of the PID | |
122 | * controller constants in struct thermal_zone_parameters. | |
e055bb0f JM |
123 | */ |
124 | static void estimate_pid_constants(struct thermal_zone_device *tz, | |
125 | u32 sustainable_power, int trip_switch_on, | |
90a99654 | 126 | int control_temp) |
e055bb0f JM |
127 | { |
128 | int ret; | |
129 | int switch_on_temp; | |
130 | u32 temperature_threshold; | |
e34a7233 | 131 | s32 k_i; |
e055bb0f JM |
132 | |
133 | ret = tz->ops->get_trip_temp(tz, trip_switch_on, &switch_on_temp); | |
134 | if (ret) | |
135 | switch_on_temp = 0; | |
136 | ||
137 | temperature_threshold = control_temp - switch_on_temp; | |
44241628 AA |
138 | /* |
139 | * estimate_pid_constants() tries to find appropriate default | |
140 | * values for thermal zones that don't provide them. If a | |
141 | * system integrator has configured a thermal zone with two | |
142 | * passive trip points at the same temperature, that person | |
143 | * hasn't put any effort to set up the thermal zone properly | |
144 | * so just give up. | |
145 | */ | |
146 | if (!temperature_threshold) | |
147 | return; | |
e055bb0f | 148 | |
90a99654 LL |
149 | tz->tzp->k_po = int_to_frac(sustainable_power) / |
150 | temperature_threshold; | |
e055bb0f | 151 | |
90a99654 LL |
152 | tz->tzp->k_pu = int_to_frac(2 * sustainable_power) / |
153 | temperature_threshold; | |
e055bb0f | 154 | |
90a99654 LL |
155 | k_i = tz->tzp->k_pu / 10; |
156 | tz->tzp->k_i = k_i > 0 ? k_i : 1; | |
e34a7233 | 157 | |
e055bb0f JM |
158 | /* |
159 | * The default for k_d and integral_cutoff is 0, so we can | |
160 | * leave them as they are. | |
161 | */ | |
162 | } | |
163 | ||
eda1ecfa LL |
164 | /** |
165 | * get_sustainable_power() - Get the right sustainable power | |
166 | * @tz: thermal zone for which to estimate the constants | |
167 | * @params: parameters for the power allocator governor | |
168 | * @control_temp: target temperature for the power allocator governor | |
169 | * | |
170 | * This function is used for getting the proper sustainable power value based | |
171 | * on variables which might be updated by the user sysfs interface. If that | |
172 | * happen the new value is going to be estimated and updated. It is also used | |
173 | * after thermal zone binding, where the initial values where set to 0. | |
174 | */ | |
175 | static u32 get_sustainable_power(struct thermal_zone_device *tz, | |
176 | struct power_allocator_params *params, | |
177 | int control_temp) | |
178 | { | |
179 | u32 sustainable_power; | |
180 | ||
181 | if (!tz->tzp->sustainable_power) | |
182 | sustainable_power = estimate_sustainable_power(tz); | |
183 | else | |
184 | sustainable_power = tz->tzp->sustainable_power; | |
185 | ||
186 | /* Check if it's init value 0 or there was update via sysfs */ | |
187 | if (sustainable_power != params->sustainable_power) { | |
188 | estimate_pid_constants(tz, sustainable_power, | |
90a99654 | 189 | params->trip_switch_on, control_temp); |
eda1ecfa LL |
190 | |
191 | /* Do the estimation only once and make available in sysfs */ | |
192 | tz->tzp->sustainable_power = sustainable_power; | |
193 | params->sustainable_power = sustainable_power; | |
194 | } | |
195 | ||
196 | return sustainable_power; | |
197 | } | |
198 | ||
6b775e87 JM |
199 | /** |
200 | * pid_controller() - PID controller | |
201 | * @tz: thermal zone we are operating in | |
6b775e87 JM |
202 | * @control_temp: the target temperature in millicelsius |
203 | * @max_allocatable_power: maximum allocatable power for this thermal zone | |
204 | * | |
205 | * This PID controller increases the available power budget so that the | |
206 | * temperature of the thermal zone gets as close as possible to | |
207 | * @control_temp and limits the power if it exceeds it. k_po is the | |
208 | * proportional term when we are overshooting, k_pu is the | |
209 | * proportional term when we are undershooting. integral_cutoff is a | |
210 | * threshold below which we stop accumulating the error. The | |
211 | * accumulated error is only valid if the requested power will make | |
212 | * the system warmer. If the system is mostly idle, there's no point | |
213 | * in accumulating positive error. | |
214 | * | |
215 | * Return: The power budget for the next period. | |
216 | */ | |
217 | static u32 pid_controller(struct thermal_zone_device *tz, | |
17e8351a | 218 | int control_temp, |
6b775e87 JM |
219 | u32 max_allocatable_power) |
220 | { | |
221 | s64 p, i, d, power_range; | |
222 | s32 err, max_power_frac; | |
e055bb0f | 223 | u32 sustainable_power; |
6b775e87 JM |
224 | struct power_allocator_params *params = tz->governor_data; |
225 | ||
226 | max_power_frac = int_to_frac(max_allocatable_power); | |
227 | ||
eda1ecfa | 228 | sustainable_power = get_sustainable_power(tz, params, control_temp); |
e055bb0f | 229 | |
bb404db4 | 230 | err = control_temp - tz->temperature; |
6b775e87 JM |
231 | err = int_to_frac(err); |
232 | ||
233 | /* Calculate the proportional term */ | |
234 | p = mul_frac(err < 0 ? tz->tzp->k_po : tz->tzp->k_pu, err); | |
235 | ||
236 | /* | |
237 | * Calculate the integral term | |
238 | * | |
239 | * if the error is less than cut off allow integration (but | |
240 | * the integral is limited to max power) | |
241 | */ | |
242 | i = mul_frac(tz->tzp->k_i, params->err_integral); | |
243 | ||
244 | if (err < int_to_frac(tz->tzp->integral_cutoff)) { | |
245 | s64 i_next = i + mul_frac(tz->tzp->k_i, err); | |
246 | ||
79211c8e | 247 | if (abs(i_next) < max_power_frac) { |
6b775e87 JM |
248 | i = i_next; |
249 | params->err_integral += err; | |
250 | } | |
251 | } | |
252 | ||
253 | /* | |
254 | * Calculate the derivative term | |
255 | * | |
256 | * We do err - prev_err, so with a positive k_d, a decreasing | |
257 | * error (i.e. driving closer to the line) results in less | |
258 | * power being applied, slowing down the controller) | |
259 | */ | |
260 | d = mul_frac(tz->tzp->k_d, err - params->prev_err); | |
b39d2dd5 | 261 | d = div_frac(d, jiffies_to_msecs(tz->passive_delay_jiffies)); |
6b775e87 JM |
262 | params->prev_err = err; |
263 | ||
264 | power_range = p + i + d; | |
265 | ||
266 | /* feed-forward the known sustainable dissipatable power */ | |
e055bb0f | 267 | power_range = sustainable_power + frac_to_int(power_range); |
6b775e87 | 268 | |
6828a471 JM |
269 | power_range = clamp(power_range, (s64)0, (s64)max_allocatable_power); |
270 | ||
271 | trace_thermal_power_allocator_pid(tz, frac_to_int(err), | |
272 | frac_to_int(params->err_integral), | |
273 | frac_to_int(p), frac_to_int(i), | |
274 | frac_to_int(d), power_range); | |
275 | ||
276 | return power_range; | |
6b775e87 JM |
277 | } |
278 | ||
345a8af7 LL |
279 | /** |
280 | * power_actor_set_power() - limit the maximum power a cooling device consumes | |
281 | * @cdev: pointer to &thermal_cooling_device | |
282 | * @instance: thermal instance to update | |
283 | * @power: the power in milliwatts | |
284 | * | |
285 | * Set the cooling device to consume at most @power milliwatts. The limit is | |
286 | * expected to be a cap at the maximum power consumption. | |
287 | * | |
288 | * Return: 0 on success, -EINVAL if the cooling device does not | |
289 | * implement the power actor API or -E* for other failures. | |
290 | */ | |
291 | static int | |
292 | power_actor_set_power(struct thermal_cooling_device *cdev, | |
293 | struct thermal_instance *instance, u32 power) | |
294 | { | |
295 | unsigned long state; | |
296 | int ret; | |
297 | ||
298 | ret = cdev->ops->power2state(cdev, power, &state); | |
299 | if (ret) | |
300 | return ret; | |
301 | ||
302 | instance->target = clamp_val(state, instance->lower, instance->upper); | |
303 | mutex_lock(&cdev->lock); | |
ab39c885 | 304 | __thermal_cdev_update(cdev); |
345a8af7 | 305 | mutex_unlock(&cdev->lock); |
345a8af7 LL |
306 | |
307 | return 0; | |
308 | } | |
309 | ||
6b775e87 JM |
310 | /** |
311 | * divvy_up_power() - divvy the allocated power between the actors | |
312 | * @req_power: each actor's requested power | |
313 | * @max_power: each actor's maximum available power | |
314 | * @num_actors: size of the @req_power, @max_power and @granted_power's array | |
315 | * @total_req_power: sum of @req_power | |
316 | * @power_range: total allocated power | |
317 | * @granted_power: output array: each actor's granted power | |
318 | * @extra_actor_power: an appropriately sized array to be used in the | |
319 | * function as temporary storage of the extra power given | |
320 | * to the actors | |
321 | * | |
322 | * This function divides the total allocated power (@power_range) | |
323 | * fairly between the actors. It first tries to give each actor a | |
324 | * share of the @power_range according to how much power it requested | |
325 | * compared to the rest of the actors. For example, if only one actor | |
326 | * requests power, then it receives all the @power_range. If | |
327 | * three actors each requests 1mW, each receives a third of the | |
328 | * @power_range. | |
329 | * | |
330 | * If any actor received more than their maximum power, then that | |
331 | * surplus is re-divvied among the actors based on how far they are | |
332 | * from their respective maximums. | |
333 | * | |
334 | * Granted power for each actor is written to @granted_power, which | |
335 | * should've been allocated by the calling function. | |
336 | */ | |
337 | static void divvy_up_power(u32 *req_power, u32 *max_power, int num_actors, | |
338 | u32 total_req_power, u32 power_range, | |
339 | u32 *granted_power, u32 *extra_actor_power) | |
340 | { | |
341 | u32 extra_power, capped_extra_power; | |
342 | int i; | |
343 | ||
344 | /* | |
345 | * Prevent division by 0 if none of the actors request power. | |
346 | */ | |
347 | if (!total_req_power) | |
348 | total_req_power = 1; | |
349 | ||
350 | capped_extra_power = 0; | |
351 | extra_power = 0; | |
352 | for (i = 0; i < num_actors; i++) { | |
f9d03814 | 353 | u64 req_range = (u64)req_power[i] * power_range; |
6b775e87 | 354 | |
ea54cac9 JM |
355 | granted_power[i] = DIV_ROUND_CLOSEST_ULL(req_range, |
356 | total_req_power); | |
6b775e87 JM |
357 | |
358 | if (granted_power[i] > max_power[i]) { | |
359 | extra_power += granted_power[i] - max_power[i]; | |
360 | granted_power[i] = max_power[i]; | |
361 | } | |
362 | ||
363 | extra_actor_power[i] = max_power[i] - granted_power[i]; | |
364 | capped_extra_power += extra_actor_power[i]; | |
365 | } | |
366 | ||
367 | if (!extra_power) | |
368 | return; | |
369 | ||
370 | /* | |
371 | * Re-divvy the reclaimed extra among actors based on | |
372 | * how far they are from the max | |
373 | */ | |
374 | extra_power = min(extra_power, capped_extra_power); | |
375 | if (capped_extra_power > 0) | |
6e3e14c9 | 376 | for (i = 0; i < num_actors; i++) { |
377 | u64 extra_range = (u64)extra_actor_power[i] * extra_power; | |
378 | granted_power[i] += DIV_ROUND_CLOSEST_ULL(extra_range, | |
379 | capped_extra_power); | |
380 | } | |
6b775e87 JM |
381 | } |
382 | ||
383 | static int allocate_power(struct thermal_zone_device *tz, | |
17e8351a | 384 | int control_temp) |
6b775e87 JM |
385 | { |
386 | struct thermal_instance *instance; | |
387 | struct power_allocator_params *params = tz->governor_data; | |
388 | u32 *req_power, *max_power, *granted_power, *extra_actor_power; | |
d5f83109 JM |
389 | u32 *weighted_req_power; |
390 | u32 total_req_power, max_allocatable_power, total_weighted_req_power; | |
6828a471 | 391 | u32 total_granted_power, power_range; |
6b775e87 JM |
392 | int i, num_actors, total_weight, ret = 0; |
393 | int trip_max_desired_temperature = params->trip_max_desired_temperature; | |
394 | ||
6b775e87 JM |
395 | num_actors = 0; |
396 | total_weight = 0; | |
397 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
398 | if ((instance->trip == trip_max_desired_temperature) && | |
399 | cdev_is_power_actor(instance->cdev)) { | |
400 | num_actors++; | |
401 | total_weight += instance->weight; | |
402 | } | |
403 | } | |
404 | ||
63561fe3 DL |
405 | if (!num_actors) |
406 | return -ENODEV; | |
97584d18 | 407 | |
6b775e87 | 408 | /* |
d5f83109 JM |
409 | * We need to allocate five arrays of the same size: |
410 | * req_power, max_power, granted_power, extra_actor_power and | |
411 | * weighted_req_power. They are going to be needed until this | |
412 | * function returns. Allocate them all in one go to simplify | |
413 | * the allocation and deallocation logic. | |
6b775e87 JM |
414 | */ |
415 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*max_power)); | |
416 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*granted_power)); | |
417 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*extra_actor_power)); | |
d5f83109 | 418 | BUILD_BUG_ON(sizeof(*req_power) != sizeof(*weighted_req_power)); |
9751a9e4 | 419 | req_power = kcalloc(num_actors * 5, sizeof(*req_power), GFP_KERNEL); |
63561fe3 DL |
420 | if (!req_power) |
421 | return -ENOMEM; | |
6b775e87 JM |
422 | |
423 | max_power = &req_power[num_actors]; | |
424 | granted_power = &req_power[2 * num_actors]; | |
425 | extra_actor_power = &req_power[3 * num_actors]; | |
d5f83109 | 426 | weighted_req_power = &req_power[4 * num_actors]; |
6b775e87 JM |
427 | |
428 | i = 0; | |
d5f83109 | 429 | total_weighted_req_power = 0; |
6b775e87 JM |
430 | total_req_power = 0; |
431 | max_allocatable_power = 0; | |
432 | ||
433 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
434 | int weight; | |
435 | struct thermal_cooling_device *cdev = instance->cdev; | |
436 | ||
437 | if (instance->trip != trip_max_desired_temperature) | |
438 | continue; | |
439 | ||
440 | if (!cdev_is_power_actor(cdev)) | |
441 | continue; | |
442 | ||
ecd1d2a3 | 443 | if (cdev->ops->get_requested_power(cdev, &req_power[i])) |
6b775e87 JM |
444 | continue; |
445 | ||
446 | if (!total_weight) | |
447 | weight = 1 << FRAC_BITS; | |
448 | else | |
449 | weight = instance->weight; | |
450 | ||
d5f83109 | 451 | weighted_req_power[i] = frac_to_int(weight * req_power[i]); |
6b775e87 | 452 | |
8132df3a LL |
453 | if (cdev->ops->state2power(cdev, instance->lower, |
454 | &max_power[i])) | |
6b775e87 JM |
455 | continue; |
456 | ||
457 | total_req_power += req_power[i]; | |
458 | max_allocatable_power += max_power[i]; | |
d5f83109 | 459 | total_weighted_req_power += weighted_req_power[i]; |
6b775e87 JM |
460 | |
461 | i++; | |
462 | } | |
463 | ||
bb404db4 | 464 | power_range = pid_controller(tz, control_temp, max_allocatable_power); |
6b775e87 | 465 | |
d5f83109 JM |
466 | divvy_up_power(weighted_req_power, max_power, num_actors, |
467 | total_weighted_req_power, power_range, granted_power, | |
468 | extra_actor_power); | |
6b775e87 | 469 | |
6828a471 | 470 | total_granted_power = 0; |
6b775e87 JM |
471 | i = 0; |
472 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
473 | if (instance->trip != trip_max_desired_temperature) | |
474 | continue; | |
475 | ||
476 | if (!cdev_is_power_actor(instance->cdev)) | |
477 | continue; | |
478 | ||
479 | power_actor_set_power(instance->cdev, instance, | |
480 | granted_power[i]); | |
6828a471 | 481 | total_granted_power += granted_power[i]; |
6b775e87 JM |
482 | |
483 | i++; | |
484 | } | |
485 | ||
6828a471 JM |
486 | trace_thermal_power_allocator(tz, req_power, total_req_power, |
487 | granted_power, total_granted_power, | |
488 | num_actors, power_range, | |
bb404db4 KS |
489 | max_allocatable_power, tz->temperature, |
490 | control_temp - tz->temperature); | |
6828a471 | 491 | |
cf736ea6 | 492 | kfree(req_power); |
6b775e87 JM |
493 | |
494 | return ret; | |
495 | } | |
496 | ||
8b7b390f JM |
497 | /** |
498 | * get_governor_trips() - get the number of the two trip points that are key for this governor | |
499 | * @tz: thermal zone to operate on | |
500 | * @params: pointer to private data for this governor | |
501 | * | |
502 | * The power allocator governor works optimally with two trips points: | |
503 | * a "switch on" trip point and a "maximum desired temperature". These | |
504 | * are defined as the first and last passive trip points. | |
505 | * | |
506 | * If there is only one trip point, then that's considered to be the | |
507 | * "maximum desired temperature" trip point and the governor is always | |
508 | * on. If there are no passive or active trip points, then the | |
509 | * governor won't do anything. In fact, its throttle function | |
510 | * won't be called at all. | |
511 | */ | |
512 | static void get_governor_trips(struct thermal_zone_device *tz, | |
513 | struct power_allocator_params *params) | |
6b775e87 | 514 | { |
8b7b390f | 515 | int i, last_active, last_passive; |
6b775e87 JM |
516 | bool found_first_passive; |
517 | ||
518 | found_first_passive = false; | |
8b7b390f JM |
519 | last_active = INVALID_TRIP; |
520 | last_passive = INVALID_TRIP; | |
6b775e87 | 521 | |
e5bfcd30 | 522 | for (i = 0; i < tz->num_trips; i++) { |
6b775e87 | 523 | enum thermal_trip_type type; |
8b7b390f | 524 | int ret; |
6b775e87 JM |
525 | |
526 | ret = tz->ops->get_trip_type(tz, i, &type); | |
8b7b390f JM |
527 | if (ret) { |
528 | dev_warn(&tz->device, | |
529 | "Failed to get trip point %d type: %d\n", i, | |
530 | ret); | |
531 | continue; | |
532 | } | |
6b775e87 | 533 | |
8b7b390f JM |
534 | if (type == THERMAL_TRIP_PASSIVE) { |
535 | if (!found_first_passive) { | |
6b775e87 JM |
536 | params->trip_switch_on = i; |
537 | found_first_passive = true; | |
8b7b390f JM |
538 | } else { |
539 | last_passive = i; | |
6b775e87 | 540 | } |
8b7b390f JM |
541 | } else if (type == THERMAL_TRIP_ACTIVE) { |
542 | last_active = i; | |
6b775e87 JM |
543 | } else { |
544 | break; | |
545 | } | |
546 | } | |
547 | ||
8b7b390f | 548 | if (last_passive != INVALID_TRIP) { |
6b775e87 | 549 | params->trip_max_desired_temperature = last_passive; |
8b7b390f JM |
550 | } else if (found_first_passive) { |
551 | params->trip_max_desired_temperature = params->trip_switch_on; | |
552 | params->trip_switch_on = INVALID_TRIP; | |
6b775e87 | 553 | } else { |
8b7b390f JM |
554 | params->trip_switch_on = INVALID_TRIP; |
555 | params->trip_max_desired_temperature = last_active; | |
6b775e87 | 556 | } |
6b775e87 JM |
557 | } |
558 | ||
559 | static void reset_pid_controller(struct power_allocator_params *params) | |
560 | { | |
561 | params->err_integral = 0; | |
562 | params->prev_err = 0; | |
563 | } | |
564 | ||
0952177f | 565 | static void allow_maximum_power(struct thermal_zone_device *tz, bool update) |
6b775e87 JM |
566 | { |
567 | struct thermal_instance *instance; | |
568 | struct power_allocator_params *params = tz->governor_data; | |
d3b60ed9 | 569 | u32 req_power; |
6b775e87 JM |
570 | |
571 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
d3b60ed9 LL |
572 | struct thermal_cooling_device *cdev = instance->cdev; |
573 | ||
6b775e87 JM |
574 | if ((instance->trip != params->trip_max_desired_temperature) || |
575 | (!cdev_is_power_actor(instance->cdev))) | |
576 | continue; | |
577 | ||
578 | instance->target = 0; | |
d0b7306d | 579 | mutex_lock(&instance->cdev->lock); |
d3b60ed9 LL |
580 | /* |
581 | * Call for updating the cooling devices local stats and avoid | |
582 | * periods of dozen of seconds when those have not been | |
583 | * maintained. | |
584 | */ | |
585 | cdev->ops->get_requested_power(cdev, &req_power); | |
586 | ||
0952177f LL |
587 | if (update) |
588 | __thermal_cdev_update(instance->cdev); | |
589 | ||
d0b7306d | 590 | mutex_unlock(&instance->cdev->lock); |
6b775e87 JM |
591 | } |
592 | } | |
593 | ||
7a583405 LL |
594 | /** |
595 | * check_power_actors() - Check all cooling devices and warn when they are | |
596 | * not power actors | |
597 | * @tz: thermal zone to operate on | |
598 | * | |
599 | * Check all cooling devices in the @tz and warn every time they are missing | |
600 | * power actor API. The warning should help to investigate the issue, which | |
601 | * could be e.g. lack of Energy Model for a given device. | |
602 | * | |
603 | * Return: 0 on success, -EINVAL if any cooling device does not implement | |
604 | * the power actor API. | |
605 | */ | |
606 | static int check_power_actors(struct thermal_zone_device *tz) | |
607 | { | |
608 | struct thermal_instance *instance; | |
609 | int ret = 0; | |
610 | ||
611 | list_for_each_entry(instance, &tz->thermal_instances, tz_node) { | |
612 | if (!cdev_is_power_actor(instance->cdev)) { | |
613 | dev_warn(&tz->device, "power_allocator: %s is not a power actor\n", | |
614 | instance->cdev->type); | |
615 | ret = -EINVAL; | |
616 | } | |
617 | } | |
618 | ||
619 | return ret; | |
620 | } | |
621 | ||
6b775e87 JM |
622 | /** |
623 | * power_allocator_bind() - bind the power_allocator governor to a thermal zone | |
624 | * @tz: thermal zone to bind it to | |
625 | * | |
8b7b390f JM |
626 | * Initialize the PID controller parameters and bind it to the thermal |
627 | * zone. | |
6b775e87 | 628 | * |
7a583405 LL |
629 | * Return: 0 on success, or -ENOMEM if we ran out of memory, or -EINVAL |
630 | * when there are unsupported cooling devices in the @tz. | |
6b775e87 JM |
631 | */ |
632 | static int power_allocator_bind(struct thermal_zone_device *tz) | |
633 | { | |
634 | int ret; | |
635 | struct power_allocator_params *params; | |
e055bb0f | 636 | int control_temp; |
6b775e87 | 637 | |
7a583405 LL |
638 | ret = check_power_actors(tz); |
639 | if (ret) | |
640 | return ret; | |
641 | ||
cf736ea6 | 642 | params = kzalloc(sizeof(*params), GFP_KERNEL); |
6b775e87 JM |
643 | if (!params) |
644 | return -ENOMEM; | |
645 | ||
f5cbb182 JM |
646 | if (!tz->tzp) { |
647 | tz->tzp = kzalloc(sizeof(*tz->tzp), GFP_KERNEL); | |
648 | if (!tz->tzp) { | |
649 | ret = -ENOMEM; | |
650 | goto free_params; | |
651 | } | |
652 | ||
653 | params->allocated_tzp = true; | |
654 | } | |
655 | ||
e055bb0f JM |
656 | if (!tz->tzp->sustainable_power) |
657 | dev_warn(&tz->device, "power_allocator: sustainable_power will be estimated\n"); | |
658 | ||
8b7b390f | 659 | get_governor_trips(tz, params); |
6b775e87 | 660 | |
e5bfcd30 | 661 | if (tz->num_trips > 0) { |
8b7b390f JM |
662 | ret = tz->ops->get_trip_temp(tz, |
663 | params->trip_max_desired_temperature, | |
664 | &control_temp); | |
665 | if (!ret) | |
666 | estimate_pid_constants(tz, tz->tzp->sustainable_power, | |
667 | params->trip_switch_on, | |
90a99654 | 668 | control_temp); |
8b7b390f | 669 | } |
6b775e87 | 670 | |
6b775e87 JM |
671 | reset_pid_controller(params); |
672 | ||
673 | tz->governor_data = params; | |
674 | ||
675 | return 0; | |
f5cbb182 JM |
676 | |
677 | free_params: | |
678 | kfree(params); | |
679 | ||
680 | return ret; | |
6b775e87 JM |
681 | } |
682 | ||
683 | static void power_allocator_unbind(struct thermal_zone_device *tz) | |
684 | { | |
f5cbb182 JM |
685 | struct power_allocator_params *params = tz->governor_data; |
686 | ||
6b775e87 | 687 | dev_dbg(&tz->device, "Unbinding from thermal zone %d\n", tz->id); |
f5cbb182 JM |
688 | |
689 | if (params->allocated_tzp) { | |
690 | kfree(tz->tzp); | |
691 | tz->tzp = NULL; | |
692 | } | |
693 | ||
cf736ea6 | 694 | kfree(tz->governor_data); |
6b775e87 JM |
695 | tz->governor_data = NULL; |
696 | } | |
697 | ||
698 | static int power_allocator_throttle(struct thermal_zone_device *tz, int trip) | |
699 | { | |
670a5e35 | 700 | int ret; |
bb404db4 | 701 | int switch_on_temp, control_temp; |
6b775e87 | 702 | struct power_allocator_params *params = tz->governor_data; |
0952177f | 703 | bool update; |
6b775e87 | 704 | |
670a5e35 | 705 | lockdep_assert_held(&tz->lock); |
63561fe3 | 706 | |
6b775e87 JM |
707 | /* |
708 | * We get called for every trip point but we only need to do | |
709 | * our calculations once | |
710 | */ | |
711 | if (trip != params->trip_max_desired_temperature) | |
670a5e35 | 712 | return 0; |
6b775e87 | 713 | |
6b775e87 JM |
714 | ret = tz->ops->get_trip_temp(tz, params->trip_switch_on, |
715 | &switch_on_temp); | |
bb404db4 | 716 | if (!ret && (tz->temperature < switch_on_temp)) { |
0952177f | 717 | update = (tz->last_temperature >= switch_on_temp); |
6b775e87 JM |
718 | tz->passive = 0; |
719 | reset_pid_controller(params); | |
0952177f | 720 | allow_maximum_power(tz, update); |
670a5e35 | 721 | return 0; |
6b775e87 JM |
722 | } |
723 | ||
724 | tz->passive = 1; | |
725 | ||
726 | ret = tz->ops->get_trip_temp(tz, params->trip_max_desired_temperature, | |
727 | &control_temp); | |
728 | if (ret) { | |
729 | dev_warn(&tz->device, | |
730 | "Failed to get the maximum desired temperature: %d\n", | |
731 | ret); | |
670a5e35 | 732 | return ret; |
6b775e87 JM |
733 | } |
734 | ||
670a5e35 | 735 | return allocate_power(tz, control_temp); |
6b775e87 JM |
736 | } |
737 | ||
738 | static struct thermal_governor thermal_gov_power_allocator = { | |
739 | .name = "power_allocator", | |
740 | .bind_to_tz = power_allocator_bind, | |
741 | .unbind_from_tz = power_allocator_unbind, | |
742 | .throttle = power_allocator_throttle, | |
743 | }; | |
57c5b2ec | 744 | THERMAL_GOVERNOR_DECLARE(thermal_gov_power_allocator); |